<!doctype html>
<div id="host"></div>
<script>
  let root = host.attachShadow({mode: 'open'});
  root.innerHTML = `
    <style>
      #test {
        color: green;
      }
    </style>
    <span id="test">Should be green</span>
    <span id="test2">Should not be green</span>
  `;
</script>
